Expanding friction-brake for motor-vehicles.



l. MXTCHELL.

EXPANDING FRICTION BRAKE FOR MOTOR VEHICLES.

APPLICATION FILED OCT- 27. 1914.

1176,3953. Patented Mar. 21,1916. v

IsAAcMI'rcHELL, or BROGKI-IOLES.

NEAR HUDDERSFIELDMENGIQAND.

EX PANDING FRICTION-BRAKE MOTOR-VEHICLES.

H Specification of Letters Patent.

Patented Mar. 21, 1916.

Application filed- October 29,1314. Serial No. 868,835.

To all whom it may concern:

Be it known that I, ISAAC MITCHELL, a

subject of the King of Great Britain and Ireland, and a resident of Erockholes, near Huddersfield, in the county ofvYork, England, ,have invented new and useful Improvements in or Appertaining to vExpanding Friction-Brakes for'Motor-Vehmles, of

which the following is a specification. .1

This invention relates to circular friction brake devices which are made in two separate halves or sections pivoting at one side :on a common stud and adapted at the opv posite side tobe forced apart or aw'ayfrom each otheriby a cam or like device to expand the brake surface against theinner surface of a rim on the wheel or driven part to apply the desired brake pressure. As the brake o as surfaces wear, the hrake'becomes more and more inefficient and there being no means provided in said type of. brake for adjustingthede'vice to compensate for such wear and team-the brake has to berenewed or a new one applied'in' its place after very little service; In other types of: internal brake devices the brake blocks-have been adjust able bodily to or from the inner surface of the brake drum byc-nuts on screwed shafts gpinions' v for actuating the brake blocks, he nuts engaging each end of each brake'block. Inf-internal; brake devices :in which the ,hrakefblocks'are. pivoted on a common stud, the .free end of one block has been adju's'tably connected to the operating lever pivoted on'the other lock, any adjust.- ment made afiecting equally'the two blocks? In externalbrakedevices, adjusting bolts or connectionsprovided with means for-adjusting same have been-employed to compensate the ad ustlng piece is apphed.

for wear of the braking surfaces.

The object of my invention is to pro- -vide, in conjunction with a brake device of and having the preferred embodiment of my invention applied thereto, and Figs. 2 and 3 show modified or alternative embodiments which will be particularly referred to. here- .c after.

Referring to the drawing, and first to Fig. 1, aand 6 represent the two halves of sections of the brake and c the stud on which they pivot. 01 represents the usual cam or like device located between the opposite ends of the brake sections and acting; when manually ope'rated'through suitable connections, to force said ends of the brake sections apart and expand them against the lnner surface Qf a rim or annulus on the wheel or driven part, such rim or annulus being represented by e. Springs f, f OOH? nec-t the two halves or sections of the brake and act to normally hold them out of eentact withw.

As previously stated, my object is to pro vide means whereby a brake device of this type can be readily adjusted to compensates cess 9 into which is adapted to loosely enter the screwed shank h of a separate adjusting plece 2'. Each shank his provided with an adjusting nut j'one face of which bears agalnst the respective end of the brake section, and the art a has apartly circular recess-k adapte to'bear against the pivot s tud.

In some cases one section only of the brake may be provided with a separate adjustingpiece as above set forth, the other section being made'as at present, as shown in Fig. 2. In this arrangement the lower brake section .is' preferably the one to which In another arrangement one split part, or

block m having an opening n therein to -accommodate the pivot stud, 'may have two screwed shanks projecting atsuitable angles from opposite sides thereof as shown at Fig.

3,'the shanks entering'recesses in the ends of the respective brake sections and being provided with adjusting nuts in the same manner asin the arrangement previously referred to. Or instead of the block m having' two shanks integral therewith, I may provide each shank with a head having an opening therein to receive the pivot stud, the, two heads occupying positions adjacent to each other on said pivot stud.

In each of the arrangements or embodimerits of the invention described, the adjusting nutsare preferably provided w1th cross grooves or recesses adapted togbe engaged 'nuts and the recesses or grooves in the ends of, the brake sections asshown at F ig. 3.

desired;

The projections and recesses may be an ranged tolock'the nuts at each half revolution, "or at each quarter of a revolution if a finer adjustment of the brake sections be The;means .set forthenable me to most effectively compensate for wear of the parts orto vary the frictional grip of the brake section or the rim or annulus. "For instance,

if in the case say of'a motor vehicle, the shaft carrying the rim or annulus wears and I allows the rim to drop somewhat, then the lower section or half, of the brake becomes useless. By means of my improvements however, I am enabled to adjust the posihave an eflicient grip. I

tion of such lower section, so

that] it may What I claim is v 1. The combination, 111 an internal circuiar friction brake, of two brake sections having a recess in the end of each section, a

common pivot for both sections at one side, a separate ad ust ng piece between each said section and the said common pivot, said adusting piece comprlsmg a screwed p n loosely engaging at'its head with the said common pivot, and which "pin freely enters i the recess in the respective end of the brake section, and an adjusting 'nut upon the pin bearing against thefend of the brake section,means for locking said adjusting nut and means for forcing the sections apart at v the other side, substantially as described.

"2. The combination, in an internal circu-.

' lar friction brake, of two brake sections having recesses in theends of such brake sec- 1' tions', a common pivot ,for both sections at one side, an'adjusting piece between each said section and the said common pivot, said adjusting piece comprising a split block riding upon the said common pivot, two

screwed shanks projecting at suitable-angles from. opposite sides thereof and which shanks enter the'recesses in the ends of the respective brake sections, adjusting nuts upon saidshanks bearing against the ends of the brake sections, means for locking the said adjusting nuts and means for forcing the sections apart at the other end, substantially as described.

In witness whereof I have hereunto set my hand in the presence of two subscribing witnesses. i

I 4 ISAAC MITCHELL.

Witnesses:

CHARLIE Coo HERBERT WHITE. 

